Scholars continue to argue about whether Ignatius' epistles give evidence of one or two groups of opponents. It is the claim of this article that Ignatius confronted a single group. We will best understand the characteristics and heritage of its members first by taking care not to overemphasise the systematic character of their thinking about Jesus, and second by setting their Christology within the context of Jewish speculation about divine mediator figures and the varieties of ‘Christian’ beliefs about Jesus. The article also compares Ignatius' positions with characteristics of Jewish Christianity and suggests that the intensity of his polemic may owe more to what he shared with this group than to the differences between them. The article concludes with some observations about the difficulties inherent in the term ‘Jewish Christianity’.